JP5314120B2 - Fusion reactor divertor curvature part machining method - Google Patents

Description

  The present invention relates to a method for processing a curvature portion of a divertor in a tokamak fusion reactor.

  Since the kinetic energy of the incident charged particles is given as heat to the tokamak fusion reactor divertor, the divertor is the device that receives the highest heat load in the fusion reactor. Therefore, the diverter is required to have a function of removing heat by withstanding such a high heat load. In order to satisfy the heat removal function of the high heat load required for the diverter, it is necessary to configure the heat receiving device of the diverter with a material having good heat conductivity.

In addition, the diverter includes a heat receiving tile on the surface in order to protect the cooling structure from thermal shock in sputtering or plasma disruption caused by ion irradiation.
When particles are scattered from the surface of the heat receiving tile by sputtering or the like and mixed into the plasma, the plasma temperature is lowered or the confinement performance is lowered. Therefore, the heat receiving tile is formed of a material having a small adverse effect on the plasma.

In a nuclear fusion reactor that discharges for a long time, the surface temperature exceeds the melting point of the constituent material in the heat capacity of the members that make up the diverter. A cooling pipe made of a copper alloy such as copper (CuCrZr) is installed, and the heat received by the heat receiving tile is forcibly removed by cooling water.
In order to absorb the difference in expansion coefficient between the heat receiving tile and the cooling pipe made of copper alloy, a buffer material made of copper material is interposed, and the heat conduction mainly between the Cu-Mg system and Ti-Cu system is made between them. Strong bonding is performed using brazing bonding using a good bonding material.

FIG. 7 is a perspective view of a diverter scheduled in the International Fuel Fusion Experimental Reactor (ITER) as an example.
The diverter in ITER is a joined body in which a heat receiving tile, a cooling pipe, a heat sink, and a support plate are combined. Since the heat receiving tile is worn out, a diverter cassette obtained by dividing the diverter into an appropriate size is disposed on the bottom of the annular tokamak vacuum vessel to form a diverter section.
In order to facilitate maintenance, the divertor cassette is provided with a high heat load heat receiving device such as a vertical target and a dome attached to the cassette body so that it can be replaced as necessary.

The ITER divertor employs a vertical target using heat receiving tiles of different materials at the lower part where the incident heat load is high and the upper part where the incident heat load is low.
At the lower part of the vertical target, since the incident thermal load is high, a carbon fiber composite material (CFC material) having a high thermal conductivity and having a low atomic number material having a small influence when mixed into plasma is used as a heat receiving tile. The formed CFC armor portion is formed. A CFC material has a higher sputtering wear rate than a metal material and has a large tritium retention, but it is suitable as an armor material because it does not cause significant thinning due to melting or outflow even in the initial disruption of operation.

On the other hand, since the incident thermal load is low at the upper part of the vertical target, tungsten or molybdenum, which is advantageous in terms of tritium retention reduction performance and durability against sputtering wear, is used as the heat receiving tile, although the thermal conductivity is lower than that of the CFC material. In ITER, tungsten armor made of tungsten is adopted.
The lower part of the vertical target has a substantially flat plane, but the upper part of the vertical target has a curved surface corresponding to the magnetic field lines in the tokamak.
The armature part of the diverter cassette is arranged with a certain number of armor assemblies that are arranged in parallel with the cooling pipe along the cooling pipe and penetrated through the cooling pipe. It is formed by fixing to the back plate with support legs provided on the heat receiving tile.

Since the CFC armor part that forms the lower part of the vertical target is substantially flat, the CFC heat receiving tile part in the armor assembly does not require a curvature part, and a large number of heat receiving tiles are fitted in a straight tubular cooling pipe. Can be formed.
However, since the carbon material and the copper alloy have poor bondability, it is preferable to metallurgically bond the heat receiving tile of the CFC armor portion to the cooling pipe in order to efficiently transmit the heat received from the plasma to the cooling pipe. In addition, since the heat-receiving tile above the vertical target is made of metal, there is no major obstacle to the adhesion with the buffer material.

Patent Document 1 discloses a carbon material block made of carbon fiber reinforced carbon composite material (CFC), a precipitation hardening type copper alloy (CuCrZr), etc. A method of manufacturing a high heat load device that satisfactorily joins the produced copper alloy cooling pipe is disclosed.
In the method for manufacturing a high heat load device disclosed in the literature, a titanium thin film layer made of titanium carbide is formed on the surface of a carbon material, and the titanium thin film layer and the copper alloy material are passed through a buffer material formed of oxygen-free copper or the like The assembly, which is placed so as to face each other and assembled by inserting a thin brazing material containing copper between the carbon material and the buffer material and between the buffer material and the copper alloy material, is vacuum brazed and subjected to an aging treatment. Thus, a high heat load device is manufactured by metallurgical joining.
The vertical target is constructed by fixing armor assemblies formed as a continuous body by stacking monoblocks of CFC and tungsten, penetrating the lower part of the vertical target and the upper part of the vertical target with one cooling pipe, and fixing them in parallel. .

  According to a conventional armor assembly processing method, a tungsten monoblock to be a heat receiving tile and a cylindrical cushioning material are joined by hot isostatic pressing (HIP) to form a heat receiving tile. Further, a mounting groove for inserting a fixing jig provided on the support plate of the back plate by forming a support leg by HIP joining a stainless steel block to be a support leg via a cushioning material to the lower surface of a part of the heat receiving tile. Then, the mounting hole for inserting the fixing pin is processed.

A CFC heat receiving tile and a tungsten heat receiving tile are sequentially inserted into a precipitation hardening type copper alloy cooling pipe to form an armor assembly intermediate product. At this time, a brazing material sheet is inserted between the heat receiving tile and the cooling pipe.
The intermediate assembly of the armor assembly is formed by repeatedly bending the upper part of the vertical target made of tungsten heat-receiving tiles little by little to form a predetermined curvature, and then heating the whole to heat-receiving tiles and cooling pipes. Are brazed to form an armor assembly.

  As described above, the armor assembly has a configuration in which the straight CFC armor portion and the tungsten armor portion having a curvature are connected in series by one cooling pipe, and an appropriate number of armor assemblies are arranged in parallel and fixed. As a result, a vertical target is formed.

JP 2011-122883 A

  However, when the armor assembly intermediate product is bent manually, it is necessary for skilled workers to manufacture it with great effort, and the workability is extremely poor, and many products are managed to have the same shape. It is difficult. In addition, when using a bending jig to form an intermediate product by sandwiching it between bending jigs and pressing it with a hydraulic machine, etc., it is more efficient than manual work, but the surface of the heat-receiving tile hit by the bending jig is damaged. , Causing heat load concentration and impurity release, the part hitting the bending jig is restrained, the heat receiving tile spacing of the formed armor assembly becomes uneven, and the heat shielding effect is biased, It is not preferable.

  Therefore, the problem to be solved by the present invention is that, in the curvature portion of the vertical target of the fusion reactor diverter, heat receiving tiles can be evenly arranged and efficiently formed in a large amount without damaging the surface of the heat receiving tile. A fusion reactor divertor curvature part machining method is provided.

  The fusion reactor divertor curvature part processing method of the present invention prepares a plurality of heat receiving tiles in which a cylindrical cushioning material is fixed to a through hole, and inserts a cooling pipe into the cushioning material of the heat receiving tile via a brazing material sheet. The formed armor assembly intermediate product is placed between a pair of bending jigs through a backing plate formed by stacking three or more metal plates so as to slide on each other, and the armature is pressed by pressing the bending jigs. The assembly intermediate product is bent to a predetermined curvature, and then heated to braze the heat receiving tile and the cooling pipe to form an armor assembly arranged on the vertical target surface of the diverter.

The heat receiving tile is made of a metal or alloy containing tungsten or molybdenum of a high-Z material, and the cooling pipe is made of a copper alloy such as chromium-zirconium copper (CuCrZr) having a large heat transfer coefficient and high strength. preferable.
The bending jig can be driven by a jack or a press.

  According to the method of the present invention, since a backing plate made of three or more metal plates is interposed between the bending jig and the armor assembly intermediate product during processing using the bending jig, the metal plate closely contacting the surface of the bending jig And a metal plate closely contacting the surface of the heat-receiving tile of the armor assembly intermediate product, with one or more middle metal plates sandwiched and slid. Therefore, the axial movement of the armor assembly intermediate product is not constrained by the bending jig, and the position of the armor assembly intermediate product surface corresponding to the protrusion at the end of the bending jig also changes as the bending curvature changes. It can move easily and can be formed with uniform curvature.

  For this reason, the space | interval of the heat receiving tile in an armor assembly intermediate manufacturing body changes with the curve of an armor assembly intermediate manufacturing body, and the heat receiving tile in the curvature part of the armor part after completion comes to arrange | position equally. In addition, since the bending jig does not directly contact the surface of the heat receiving tile, the surface of the heat receiving tile is hardly damaged, and the risk of damage during operation of the fusion reactor is reduced.

Further, since the bending of the armor assembly is formed by using a bending jig, the reproducibility of the shape is improved, and a highly accurate product can be easily manufactured. Further, if a hydraulic jack or the like is used, it can be more easily manufactured at a high speed.
For example, about 1300 armor assemblies in the diverter section are planned for ITER, but a product of the same shape can be efficiently supplied in large quantities by the method of the present invention.

  By the fusion reactor divertor curvature portion processing method of the present invention, the curvature portion of the vertical target can be efficiently formed with high reproducibility while preventing the surface of the heat receiving tile from being damaged. The fusion reactor divertor curvature part processing method of the present invention can also be applied when forming the curvature part of the dome of the diverter.

It is a conceptual diagram showing the state which set the armor assembly intermediate manufacturing body to the bending jig in the fusion reactor divertor curvature part processing method concerning one Example of this invention. It is a conceptual diagram showing the state which pressed the armor assembly intermediate manufacturing body with the bending jig in the fusion reactor divertor curvature part processing method of a present Example. It is a partially expanded front sectional view in the state where the armor assembly intermediate product was pressed with the bending jig in the fusion reactor divertor curvature part processing method of the present example. It is a partial expanded side sectional view in the state where the armor assembly intermediate manufacture was pressed with the bending jig in the fusion reactor divertor curvature part processing method of this example. It is process drawing explaining an example of the manufacture procedure of the armor assembly to which a present Example is applied. It is a side view showing the armor assembly which gave the curvature by the fusion reactor divertor curvature part processing method of the present Example. It is a perspective view showing the vertical target of the fusion reactor diverter to which this invention is applied.

  Hereinafter, the fusion reactor divertor curvature part processing method of the present invention will be described in detail using embodiments. The present embodiment is a method of forming an armor portion constituting a curvature portion of a vertical target of a diverter in a tokamak type nuclear fusion reactor.

  FIG. 1 to FIG. 6 are drawings for explaining a fusion reactor divertor curvature portion machining method of this embodiment. FIG. 1 shows a state in which an armor assembly intermediate product is set on a bending jig, and FIG. 2 shows an armor assembly. 3 represents a state in which the intermediate product is pressed with a bending jig, FIG. 3 represents a front cross-section when the armor assembly intermediate product is pressed with a bending jig, and FIG. 4 represents a side cross-section thereof. FIG. 5 is a process diagram for explaining the procedure of the fusion reactor divertor curvature part machining method according to the present embodiment. FIG. 6 is a side view of the armor assembly.

As shown in the figure, the fusion reactor divertor curvature portion processing method of the present embodiment is an armor set formed by fitting the cooling pipe 15 into the buffer material 17 of the heat receiving tile 11 in which the cylindrical buffer material 17 is fixed to the through hole. The three-dimensional intermediate product 10 is formed by giving a predetermined curvature by a press using bending jigs 21 and 23.
As shown in FIG. 1, the method of this embodiment is a pair of armor assembly intermediate manufactured body 10, with a pair of contact plates 31 and 33 formed by stacking three or more metal plates so as to slide on each other. As shown in FIG. 2, it arrange | positions between the bending jigs 21 and 23, and has the characteristics in the place which presses the bending jigs 21 and 23 and carries out curved surface processing.

  3 and 4 show a state in which the intermediate armor assembly 10 is sandwiched between the bending jigs 21 and 23 and pressed by the bending jig 23 to be hardened in an arc shape. The bending jig 23 is fixed to a jig holding table 25, and the jig holding table 25 is reciprocated toward the fixed bending jig 21 by a stem 27 connected to a piston of a hydraulic jack (not shown). If the hydraulic jack is used, the bending jig 23 can be driven at an appropriately suppressed speed in accordance with the operation of the worker.

When the curvature of the armor assembly 10 is large, instead of bending to the target curvature at once, replace with a bending jig with gradually increasing curvature so that it is bent little by little so that the target curvature is achieved by finishing. It is preferable to make it.
When the bending amount is increased step by step, the concave and convex surfaces of the bending jigs 21 and 23 used for finishing are formed to have a curvature necessary for the armor assembly intermediate product 10.

The contact plates 31 and 33 are obtained by stacking three or more stainless thin plates.
Since the contact plate 31 is interposed between the bending jig 21 and the heat receiving tile 11, the surface of the heat receiving tile 11 is not damaged by the protrusions at the end of the bending jig 21.
Further, when the armor assembly intermediate product 10 is sandwiched and pressed between the bending jigs 21 and 23, the armature assembly intermediate product 10 starts to contact the contact plate 31 from the center position of the surface of the heat receiving tile 11, and finally the entire surface of the heat receiving tile 11 is applied. Pressed against the plate 31.
When a pressing force of a predetermined level or more is applied, the position of the heat receiving tile 11 is fixed by the surface of the contact plate 31, and the heat receiving tiles 11 are fixed in a state where the distance between the adjacent heat receiving tiles 11 is not fully opened.

  However, in the method of the present embodiment, the three thin plates forming the contact plates 31 and 33 slide relative to each other, so that the contact plates 31 and 33 have a circular arc while the armor assembly intermediate product 10 is bent. Since the thin plates are displaced even when distorted, the amount of expansion or compression of the surface with which the surface of the heat-receiving tile 11 contacts is smaller than that of a single plate. Therefore, even when the bending jigs 21 and 23 are pressed against the armor assembly intermediate product 10 to increase the curvature, the distance between the adjacent heat receiving tiles 11 does not change greatly, so that the distance between the heat receiving tiles 11 in the curvature portion is almost the same. A uniform armor assembly 20 can be obtained.

  In addition, since the support leg 13 is provided in the back surface of the heat-receiving tile 11 skewered by the cooling pipe 15 at an appropriate interval, the support leg 13 is attached to the contact plate 33 that contacts the back side. A hole through is provided. The bending jig 23 is also provided with a recess that avoids the support leg 13.

Next, the manufacturing procedure of the armor assembly in the present embodiment will be described.
FIG. 5 illustrates a manufacturing process for forming a curvature portion on an upper part of a vertical target using a high-Z metal tungsten heat receiving tile in the armor assembly. In addition, since the heat-receiving tile on the upper part of the vertical target is made of metal, there is no major obstacle to the adhesion with the buffer material, and the process of preparing the armor assembly intermediate product can be simplified from the CFC armor part.

  In the armor assembly manufacturing method according to the present embodiment, as shown in FIG. 5, first, a tungsten heat receiving tile monoblock 12 and a cylindrical cushioning material 17 which are the main body of the heat receiving tile 11 are prepared. A cooling pipe through hole 41 is cut in the monoblock 12 for heat receiving tile. The cooling pipe through hole 41 is nickel-plated and the buffer material 17 is inserted, and joined by hot isostatic pressing (HIP) to form the heat receiving tile 11.

Further, a support leg block 14 made of stainless steel to be the support legs 13 and a flat cushioning material 18 are prepared, and a part of the heat receiving tile 11 is supported on the lower surface of the heat receiving tile 11 via the cushioning material 18. The leg block 14 is applied and HIP joining is performed to form the support leg 13. A mounting groove 43 for inserting a fixing jig of the back plate and a mounting hole 45 for inserting a fixing pin are processed into the support leg 13 fixed to the heat receiving tile 11.
The mounting groove 43 and the mounting hole 45 may be processed in advance in the support leg block 14 before being fixed to the heat receiving tile 11.

The armor assembly intermediate manufactured body 10 is obtained by inserting the heat receiving tile 11 in an overlapping manner into a copper alloy cooling pipe 15 made of a precipitation hardening type copper alloy or the like so that the support legs 13 come to a predetermined position. At this time, a brazing material sheet 19 is inserted between the buffer material 17 of the heat receiving tile 11 and the cooling pipe 15.
The brazing material sheet 19 includes nickel, copper, and manganese, and is used by cutting out from a sheet having a thickness of about 50 μm to a width that matches the length of the cooling pipe through hole 41.

The armor assembly intermediate manufactured body 10 is repeatedly bent little by little using the diverter curvature part processing method described above, and formed to have a predetermined curvature, and then heated and brazed and fixed. An armor assembly 20 is formed.
Note that the heat receiving tile 11 and the cooling pipe 15 of the armor assembly intermediate manufactured body 10 may be fixed by brazing before bending.

FIG. 6 is a side view showing the armor assembly 20 provided with a curvature by the fusion reactor divertor curvature part processing method of the present embodiment.
The armor assembly 20 has a configuration in which a straight CFC armor portion formed by the method of Patent Document 1 and a tungsten armor portion having a curvature formed by the method of FIG. 5 are connected in series by one cooling pipe. have.
A vertical target as shown in FIG. 7 is formed by arranging a predetermined number of armor assemblies 20 in parallel and fixing them to the back plate.
In addition, when the CFC armor portion also has a curvature, it can be bent using the divertor curvature portion processing method of the present embodiment. Furthermore, it can also be used for processing the curvature portion in the dome.

  By using the fusion reactor divertor curvature part processing method of the present embodiment, mass production of an armor assembly having a precise curvature as designed, a uniform interval between the heat receiving tiles, and no damage to the tile surface and high protection performance. be able to. By using the armor assembly manufactured by the method of this embodiment, a high-quality vertical target or dome for use in a tokamak fusion reactor can be manufactured.

  The fusion reactor divertor curvature part processing method of the present invention can be used to manufacture a large number of high-performance vertical targets and domes necessary for a high-performance tokamak fusion reactor.

10 Armor assembly intermediate product 11 Heat receiving tile 12 Heat receiving tile monoblock 13 Support leg 14 Support leg block 15 Cooling pipe 17 Buffer material 18 Buffer material 19 Brazing material sheet 20 Armor assembly 21, 23 Bending jig 25 Jig gripping base 27 Stem 31, 33 Contact plate 41 Cooling pipe through hole 43 Mounting groove 45 Mounting hole

Claims (3)

An armor assembly intermediate product formed by preparing a plurality of heat-receiving tiles in which a cylindrical cushioning material is fixed in a through hole and inserting a cooling pipe into the cushioning material via a brazing material sheet is used for three or more metals. The armor assembly intermediate product is bent to a predetermined curvature by placing the plate between a pair of bending jigs via a contact plate formed by overlapping the plates so as to slide on each other and pressing the bending jigs. A method for processing a curvature portion of a fusion reactor, wherein a heat receiving tile and a cooling pipe are brazed by heating to form an armor assembly arranged on a vertical target surface of the diverter. 2. The fusion reactor divertor curvature portion machining method according to claim 1, wherein the heat receiving tile is made of a tungsten material, and the cooling pipe is made of CuCrZr (copper alloy). 3. The fusion reactor diverter curvature part machining method according to claim 1, wherein the bending jig is driven by a jack or a press.

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